1. Field of the Invention
The present invention relates to an apparatus for liquifying substances and, more particularly, to such an apparatus which is particularly well suited to the liquification of substances embodied in a substantially amorphous mass in a substantially continuous operation.
2. Description of the Prior Art
A host of substances are manufactured, packaged, sold, and delivered to a work site in a different form than that in which they are ultimately used. This fact results from a number of considerations including that the substances may otherwise lose their efficacy, for ease of transport, to maintain the cost of such substances in a range acceptable in the marketplace and for similar considerations. As a consequence, at the time usage of the substances is to be undertaken, the substances must be converted to a different form at the job site.
For example, gypsum is widely used as a soil treatment in agriculture for the purpose of improving the permeability of the soil. Enhanced permeability permits irrigation water to be employed most effectively and efficiently and enhances the degree to which other soil additives can be successfully employed. For all of the reasons previously mentioned as well as others, gypsum is typically sold in large volumes in powdered form. The large volumes of gypsum are typically housed in bag-type containers which are delivered to the job site. While gypsum can be applied to the soil by a variety of methods, it has been found most effective to dissolve the gypsum in irrigation water which is released to the acreage to be treated through the normal irrigation system thereof. It is known in prior art methods of application to open the containers and deposit the contents into conventional liquifying devices which are employed in dissolving the gypsum in the irrigation water. Such conventional devices characteristically provide a hopper for receiving the gypsum in bulk form and use a delivery mechanism, such as an auger, for dispensing the gypsum to the irrigation water.
Such prior art devices are notoriously inadequate for the purpose. Gypsum is a powdered substance which is, in many respects, very difficult to handle in that, under any substantial pressure, the gypsum compresses to a cake like consistency. In addition, gypsum is highly water soluble. Because of these two properties, gypsum is very difficult to feed continuously since these properties cause the gypsum to "bridge" within the hopper so that it does not feed gravitationally to the distributing mechanism. The propensity for the gypsum to cake and its ability to absorb moisture from the environment, causes it to form a temporarily unitary mass extending between the walls of the hopper and resistant to movement. When the distributing mechanism has passed all of the gypsum from the area beneath the bridge, obviously no further distribution of the gypsum takes place. Since, when applied by irrigation, gypsum is usually applied in very large quantities over very large agricultural acreages, the period of time required to complete the irrigation cycle typically lasts several days. Furthermore, with such large agricultural acreages, the distributing devices are remote from personnel who might monitor the operation of the equipment. Accordingly, a chronic problem inherent in such operations is that such bridging occurs long before it is detected and can be corrected. As a consequence, significant portions of the irrigation cycle are completely devoid of the application of the gypsum thereby entirely defeating the purpose of the operation.
Other problems incident to the conventional application of gypsum and other such substances include mechanical deficiencies which result in the substance not being distributed evenly, the substance being spilled or otherwise lost in the vicinity of the equipment, the irrigation water used in the application of the substance being unintentionally released so as to cause flooding, the uneven application of the substances to the irrigation water and other such entirely unsatisfactory consequences. While these and other unsatisfactory results are particularly acute in the case of the application of gypsum in large scale agricultural irrigation, the same and other problems are inherent in the application of other substances and in other operational environments. For example, the same problems are endemic to the application of such substances as natural and chemical fertilizers, other soil additives and amendments, and, more broadly, all substances which must be converted from one form to another and particularly wherein the first form requires as a matter of practical application that the substance be contained in a substantially amorphous mass of the substance metered over a relatively long period of time in a substantially continuous operation and in which such perimeters as time, concentration, and dependable operation without supervision are critical to the achievement of the operational objectives.
Therefore, it has long been known that it would be desirable to have an apparatus for liquifying substances which has particular utility in the liquification of such substances as must, for other reasons, be dispensed from a large amorphous mass of the substance over a relatively long period of time; which has particular utility in the dispensing of such substances as gypsum and other materials which are embodied in powdered form and wherein the substances may be susceptible to bridging as a result of the absorption of moisture and/or the propensity to adhere in such a fashion as to assume a caked consistency; which automatically operates to ensure that such bridging does not take place entirely without being monitored; which affords the ability for supervisory personnel additionally to ensure that such bridging does not take place; which operates automatically to recover material which has inadvertently been released to the environment and to direct the material for usage in the manner proscribed; which can be operationally adjusted to achieve a volume of distribution over time which is entirely reliable; and which otherwise is entirely effective in achieving its operational objectives.